Final answer:
Cockayne syndrome is the inherited disorder characterized by increased sensitivity to light and neurological issues without a corresponding rise in skin cancer frequency. Xeroderma pigmentosum, on the other hand, involves a defect in DNA repair mechanisms leading to a higher risk of skin cancer.
Step-by-step explanation:
An inherited disorder characterized by acute sensitivity to light, neurological dysfunction due to neuron demyelination, and dwarfism without an evident rise in skin cancer frequency is called Cockayne syndrome. While xeroderma pigmentosum is related to heightened risk of skin cancer due to inability to repair UV-induced DNA damage, Cockayne syndrome presents a different set of symptoms and does not typically involve a higher risk of skin cancer despite increased light sensitivity.
Patients with xeroderma pigmentosum are unable to use the nucleotide excision repair mechanism to repair thymine dimers caused by UV light exposure. This defect, which results in distorted DNA structure, significantly increases their risk of contracting skin cancer compared to individuals without the condition. In contrast, Cockayne syndrome is known for symptoms such as dwarfism and nervous system problems, in addition to light sensitivity, but not an increased frequency of skin cancer.